1. Field of the Invention
The present invention relates to a vehicular damper with a vehicle height adjusting function which is applied to a vehicle such as a motor vehicle. In this specification, the term "vehicular damper" means a damper for use in a vehicle.
2. Description of the Related Art
A vehicular damper is provided with a damper main body, and a damper rod which is inserted into the damper main body so as to be movable up and down. One of the damper main body and the damper rod is connected to an unsprung member, and the other thereof is connected to a vehicle body so that a damping force against the vibrations of the unsprung member can be obtained.
In case a function of adjusting the vehicle height (also called a vehicle height adjusting function) is added to the damper, the following arrangement is employed. Namely, a cylinder for adjusting the vehicle height is interposed between the vehicle body and the damper. A pressure fluid from a pressure source is supplied to the cylinder, whereby the vehicle height is adjusted. As this pressure source, a pump to be driven by an engine of the vehicle is normally used. In this arrangement, however, the energy consumption increases and the specific fuel consumption becomes poor. As a solution, in order to enable to supply the pressure fluid without consuming the energy of the engine, there is proposed in Japanese Published Unexamined Patent Application No. 150615/1997 an art in which a heat-pressure conversion type of pressure source utilizing the waste heat of an engine is used.
This pressure source is provided with: a pressure chamber hermetically containing therein a pressure medium which changes its state between a liquid state and a gaseous state; a heating chamber for passing therethrough a heating medium which is heated by the heat generated by a driving source of the vehicle; and a fluid chamber which is contained in the pressure chamber so as to be expanded and contracted. By the rise in the internal pressure in the pressure chamber as a consequence of evaporation of the pressure medium, the pressure chamber is compressed. The pressurizing fluid is thus supplied from the fluid chamber to the vehicle height adjusting cylinder.
The above-described heat-pressure converting type of pressure source must, like the pressure source to be driven by the engine, be mounted on the vehicle body separately from the damper. Therefore, it is troublesome to mount it on the vehicle body.
In view of the above-described point, the present invention has an object of assembling the pressure source integrally with the damper to thereby improve the ease within which the damper can be mounted on the vehicle body.